I clicked the SBB2 for the first time, and it told me I was missing SRB2.srb/SRB2.wad. So, I got it from the 2.1.11 installer, but when I go to boot it again, then it won't start because it detected an extra WAD file (I'm assuming this is SRB2.srb). Can you fix this? Or am I using the wrong game version?